Presently, inter-exchange carriers, such as AT&T, carry telecommunications traffic between two local telephone exchanges that are not within the same Local Telephone Access Area (LATA). To carry inter-LATA traffic (as well as intra-LATA traffic where permitted), an inter-exchange carder typically has a gateway Point of Presence (POP) (i.e., a connection point) within a local exchange that serves as a point of entry to, or egress from, the inter-exchange carrier's network. In the case of AT&T, each of its gateway POPs is connected to other gateway POPs in a star-like arrangement by one or more express traffic links, typically fiber optic cables. These express traffic links may pass through one or more local exchanges that are devoid of a gateway POP. Traditionally, no connection exists between such an express traffic link and the local exchange unless the exchange contains a gateway POP. Thus, inter-LATA traffic from a local exchange devoid of a gateway POP of an inter-exchange carrier must pass to a local exchange where the carrier has such a gateway POP if such traffic is to pass over the inter-exchange carrier's network.
Should an express traffic link between two gateway POPs fail, (e.g., become severed or otherwise be unable to carry its normal volume of traffic), then telecommunications traffic can be routed around such a failed link through other gateway POPs in the inter-exchange carrier's network. An example of one such restoration technique is described in U.S. Pat. No. 5,182,733, issued on Jan. 26, 1993, in the name of J. Askew et al., and assigned to AT&T. Using the technique described in the Askew et al. patent, a service disruption between two inter-exchange POPs can be restored relatively quickly, thus preventing significant call blockage, and the attendant loss of revenue associated with such call blockage.
In some telecommunications networks, a gateway POP at a local exchange is connected, via a single local trunk (e.g., a fiber optic or copper cable) that terminates or "dead-ends" at one or more downstream local exchanges such that the only link between the gateway POP and the dead-ended local exchange(s) is the local trunk. If the local trunk fails, then no traffic passes between the dead-ended local exchange(s) and the gateway POP of the inter-exchange carder. Presently, there is no way to route traffic around such a local trunk should it fall. For traffic to pass between the gateway POP and a dead-ended local exchange, the local trunk linking the dead-ended local exchange(s) and the gateway POP must be physically restored, which is a time-consuming task, often taking hours to complete. Until the severed local trunk is repaired, telecommunications traffic remains blocked, causing a loss of revenue both to the local inter-exchange and the inter-exchange carrier.
Thus, there is a need for a technique for restoring service to between a dead-ended local exchange and a gateway POP.